One of the most dominant themes in the redemptive power of love.  Sparks shows love to be a force that can conquer class discrimination and social repression.  Allie's love for Noah transcends the wishes of her parents, driven by materialism and social standing.  This love is also shown to be able to redeem individuals from making mistakes that they can later regret.  The love that Allie and Noah share is filled with tempestuous moments, but these do not preclude or overwhelm the basic emotion of devotion that each feels towards the other.  This theme of love is also to be able to challenge the knowledge of medical science.  Sparks is well aware that the medical community is limited against the degenerative power of Alzheimer's Disease.  The doctors in the book readily admit that they have no answer for the condition.  They discredit Noah's reading of the notebook to her in the idea that nothing will change Allie's contraction of the disease.  Yet, Sparks' thematic development of love is one that can momentarily halt the disease and one that is demonstrative in its abilities to redeem Allie from a crippling condition.  In these instances, the theme of love and its power of redemption from both social and medical conditions is where Sparks spends most of the narrative's energies. 

The theme of maturation is another element developed in the course of the narrative.  Sparks shows love as only being possible when individuals are willing to mature and grow old with one another.  Allie and Noah believe in their love, so much so that they are willing to put all other elements of their life on hold for it.  He does not "move on" with his life, though others tell him to do so.  She does not marry for convenience, though it is the easy thing to do.  Both Allie and Noah demonstrate the theme that maturation in terms of being willing to cradle the love one has for another over a prolonged period of time.  Even when Alzheimer's threatens to take over their love, the notebook itself is a testament to how love grows over time and its prolonged strength can reclaim anyone who might be lost.  Noah does not leave Allie in the nursing home, remaining with her.  This shows how maturation is the necessary ingredient for love to develop and for its powers of redemption to be most visible.